1. Field of the Invention
This invention relates to improvements in low-noise-level internal combustion engines, more specifically to a low-noise-level internal combustion engine of the kind having a skeletal support for the crankshaft main bearings and wherein the sound through solids stimulated parts of the engine cylinder block, cylinder head and auxiliaries rigidly secured to the cylinder head are connected together, and a composite crankcase and flywheel casing is connected to said parts by at least one sound-absorbing element.
2. Description of the Prior Art
At this construction the vibration generating parts of the engine cannot transmit the vibrations to the composite crankcase and flywheel casing because of the sound-absorbing mounting. Apart from the advantage of reduced overall weight this arrangement presents the main advantage that the crankcase and the flywheel casing require no further sound-absorbing provisions whatsoever because all of these parts are already acoustically insulated relative to the skeletal engine unit support which is itself subject to the operative forces and resulting vibrations.
In the DE-OS No. 2 612 182 an internal combustion engine of said construction is described, having the cylinders arranged in a single line.